What is one of the fears of a musician who plays live shows? I will tell you one of my worries. I am afraid I will show up at the gig and not have my guitar, a mic, harmonica, harmonica holder, music, etc. We all have certain items that we have to have to do our shows. Your list might be even longer than mine. 

I set up everything at home just like I would do if I was going to do a gig. I play a couple songs and tear it down. When I tear it down I set it by the door or in the back of my pickup truck.( if it isn't raining.) Yes it does rain almost every time I have a gig. Considering the drought conditions in Kansas you can probably figure out I have not been playing live often enough. By doing it this way I know that I have the cord to my guitar or the electrical cord to my amp. It works for me and it might work for you. 

I also pack a few extra items that I might need. Tape, extra cords, tip jar, pen, notebook, etc. I feel like a boy scout without a merit badge.  The main thing to do is to have fun.